CN1205776C - Signal transmission device and signal transmission method - Google Patents

Abstract

The present invention relates to a signal transmission device and a signal transmission method. The signal transmission device includes a first communication device for transmitting a signal through a plurality of high-speed serial buses, and a first communication device for transmitting a signal through a low-speed serial bus. A second communication device for transmitting a signal to the low-speed serial bus of the high-speed serial bus; a transmission line is composed of the multiple high-speed serial buses and the low-speed serial bus, and each signal transmission device Provided on the terminal side of the transmission line, a signal transmission operation through the high-speed serial bus is controlled based on a result of communication through the low-speed serial bus.

Description

Signal transmission device and signal transmission method

technical field

The invention relates to a signal transmission device and a signal transmission method. Especially in signal transmission, in the case of transmitting signals through a transmission line, the transmission line is composed of a plurality of high-speed serial buses and a low-speed serial bus whose transmission speed is lower than the transmission speed of the high-speed serial bus, through Signal transmission operations of the plurality of high-speed serial buses are controlled based on results of communications through the low-speed serial buses.

Background technique

As is well known, computer equipment or similar equipment can convert a digital image signal into an analog image signal, and transmit it to a display device through analog transmission. However, with the expansion of display devices, the display units of which are driven by digital signals, such as liquid crystal displays; in order to prevent the degradation of image quality and reduce costs, a method of transmitting image signals as digital signals has become standard. For example, the DVI (Digital Visual Interface, Version 1.0) standard has been specified by the DDWG (Digital Display Working Group). According to the DVI standard, digital image signals are transmitted using a TMDS (Transition Minimized Differential Signaling) link developed by Silicon Image Corporation of the United States. The interface provides data transmission lines and a channel clock transmission line for respective channels of red, green and blue, and image signals of the respective channels of red, green and blue are transmitted using a baseband. In addition, the interface includes an I ² C bus, which is a bidirectional serial transmission line whose ^transmission speed is lower than that of the high-speed serial bus of the TMDS link. As a transmission line, the I ² C bus is used as a transmission line of the DDC (Display Data Channel) standard with a plug-and-play function, which has been specified by VESA (Video Electronics Standards Association).

Meanwhile, the wiring method of the DVI standard is such that a transmitting device such as a computer device is connected with a receiving device such as a display device in a point-to-point manner. In this way, the image signals of the respective channels of red, green and blue are digitally transmitted unidirectionally from the transmitting device to the receiving device, and are transmitted at high speed on the baseband by using the TMDS link. Here, audio signals, data signals, etc., cannot be transmitted at high speed. In addition, due to the plug-and-play function, it is necessary to determine whether the digital image signal is transmitted by using the six-channel data transmission line of the TMDS channel, or by using the three-channel data transmission line of the TMDS channel. Here, when the transmission of the digital image signal is set to use three-channel data transmission lines for transmission, the remaining three-channel data transmission lines are reserved for backup, so the data transmission lines are not fully utilized. Also, respective image signals of red, green, and blue are transmitted in accordance with GTF (Generalized Timing Format) prescribed by VESA. Here, since a blanking period is reserved according to the GTF standard, even in digital signal transmission, the transmission efficiency is not high enough.

Contents of the invention

The first object of the present invention is to provide a data transmission device and a data transmission method capable of effectively transmitting signals. In its wiring mode, multiple high-speed serial buses and one The low-speed serial bus is connected by an identical connector.

A second object of the present invention is to provide a signal transmission device that transmits signals through a transmission line consisting of a plurality of high-speed serial buses and a low-speed serial bus whose transmission speed is lower than that of the high-speed serial bus; The signal transmission device includes: a first communication device for transmitting at least one signal through the plurality of high-speed serial buses, and a second communication device for transmitting a signal through the low-speed serial bus; As a result of the communication of the low-speed serial bus, the second communication device controls the signal transmission operation of the first communication device; and based on the communication result of the second communication device, the multiple The signal transmission direction of the root serial bus can be set independently by the first communication means.

The third object of the present invention is to provide a signal transmission method, comprising the steps of: preparing at least two signal transmission devices, each device including a first communication device for transmitting at least one signal through multiple high-speed serial buses, and a second communication device for transmitting a signal through a low-speed serial bus whose transmission speed is lower than that of the high-speed serial bus; the signal transmission device is arranged at opposite ends of a transmission line composed of said plurality of high-speed serial buses and one low-speed serial bus; controlling a signal transmission operation through said high-speed serial bus based on a communication result through said low-speed serial bus; and a signal in the signal transmission operation a transmission direction through said plurality of serial buses having said first transmission speed, and based on a result of communication via said serial bus having said second transmission speed, determined by said serial bus having said first transmission speed The respective serial buses are set independently.

According to the present invention, when a signal is transmitted through a transmission line consisting of a plurality of high-speed serial buses and a low-speed serial bus whose transmission speed is lower than that of the high-speed serial bus, based on passing through the low-speed serial bus As a result of the communication, the signal transmission directions of the high-speed serial buses are set independently, and image signals and sound signals are transmitted through different high-speed serial buses. Alternatively, the sound signal may be transmitted in a multiplexed fashion during the blanking period of the image signal. In addition, multiple transmission lines may be connected to each signal transmission device. Moreover, when the opposite signal transmission device has a separate signal recording function, and the content transmitted through the high-speed serial bus is copyright protected and copy-prohibited, based on the results of communication through the low-speed serial bus, Signal transmission operations via the high-speed serial bus are also prohibited.

Description of drawings

The block diagram of Fig. 1 shows the structure of a kind of signal transmission system of the first embodiment of the present invention;

The block diagram of Fig. 2 shows the partial structure of a kind of transmission/reception unit forming the second embodiment of the present invention;

The graph of Fig. 3 shows the bandwidth of a kind of TMDS link of the present invention;

The block diagram of Fig. 4 shows the structure forming a kind of signal transmission system of the third embodiment of the present invention;

The block diagram of Fig. 5 shows the structure of a kind of signal transmission system forming the fourth embodiment of the present invention;

Figure 6 shows the format of a multiplexed signal (DM _a ) for illustrating the operation of the present invention;

Figure 7 is a schematic front view showing a network forming a fifth embodiment of the invention; and

Figure 8 is a schematic front view showing a point-to-point connection with a plurality of transmission lines forming a sixth embodiment of the invention.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows the structure of a signal transmission system according to the first embodiment of the present invention. A first signal transmission device 10 and a second signal transmission device 20 are connected through a transmission line 30 . The transmission line 30 is composed of a plurality of high-speed serial buses 301-307 and a low-speed serial bus 310 whose transmission speed is lower than that of the high-speed serial buses 301-307.

The signal transmission device 10 includes an image transmission processing unit 11 that generates an image signal as its content. More specifically, the image transmission processing unit 11 generates a serial image signal DG _a of three primary colors by adjusting the resolution and the number of colors based on an image control signal TG _a fed from a control unit 19 to be described below, and then converts the The generated signal DG _a is fed to a transmission/reception unit 13 . Likewise, a clock signal CK _a , a horizontal and vertical synchronizing signal SY _a , and an enable signal _EN a allowing identification between an active display period and a blanking period are used for each of the three A signal of the serial image signal DG _a of primary colors is fed from the image transmission processing unit 11 to the transmission/reception unit 13 .

Next, the structure of the transmission/reception unit 13 is described. In the system shown in Figure 1, the high-speed serial buses 301-307 of the transmission line 30 include high-speed serial buses 301-306 used in six-channel data transmission, such as a TMDS link, and a The high-speed serial bus 307 in the clock transmission of the transmission clock signal for the signals transmitted by the six-lane high-speed serial buses 301-306. Therefore, FIG. 2 shows the structure of the transmission/reception unit 13 forming the second embodiment of the present invention, and only the data transmission high speed serial bus and the clock transmission high speed serial bus of one channel will be exemplified. Since the data transmission high-speed serial bus of other channels is similar to the exemplified one, their descriptions are omitted.

A serial image signal to be transmitted corresponding to one of the three primary colors, for example, a blue serial image signal DG _aB and the enable signal EN _a are fed to a multiplexer (multiplexer) 131, and the The clock signal CK _a is fed to a PLL circuit 132 . Furthermore, the synchronization signal SY _a is fed to said multiplexer 131 , which has been fed with said blue serial image signal DG _aB .

Here, the serial image signal is transmitted in compliance with GTF or a Monitor Timing Specification specified by VESA, and a blanking period is reserved in such a standard. Thus, a multiplex signal DM _a is generated in the multiplexer 131 in such a way that, based on the enable signal EN _a , the blue serial image signal DG _aB and the synchronization signal SY _a is selected in a time-division manner during the active display period and the blanking period, respectively. The multiplexed signal DM _a generated by the multiplexer 131 is fed to an encoder 133 . Incidentally, the multiplexer 131 is an operation control signal TM fed from the control unit 19 regardless of whether the multiplexed signal DM _a is generated by the multiplexer 131. controlled by _a .

The PLL circuit 132 generates a reference signal CK _am synchronized with the clock signal CK _a and feeds the generated signal to the encoder 133 . Furthermore, it feeds said feed clock signal CK _a to the transmitters 134 and 135 .

After equalizing the DC level of the multiplex signal DM _a fed from the multiplexer 131, and minimizing the number of inversions (inversions) of the logic level of the multiplex signal DM _a , the encoding Transmitter 133 generates a transmission signal DT, which then feeds the generated signal to transmitter 135. Incidentally, the generation of the transmission signal DT is done at a certain timing based on the reference signal CK _am .

The output terminals of the transmitters 134 and 135 are connected to the transmission line 30 and receive the transmission/reception control signal TD fed from the control unit 19 . In the respective transmitters 134 and 135, both the clock signal CK _a fed from the PLL circuit 132 and the transmission signal DT fed from the encoder 133 are output to one end of the transmission line 30, and The transmission line 30 is controlled based on the fed transmission/reception control signal TD. Incidentally, the output processing of the transmission signal DT is performed at a certain timing based on the clock signal CK _a .

The input of a receiver 141 is connected to the output of the transmitter 134 , and the input of a receiver 142 is connected to the output of the transmitter 135 . The receivers 141, 142 are also fed with the transmit/receive control signal TD. Thus, when the transmission signal DT and the clock signal CK _a are respectively output from the respective transmitters 134 and 135, the receiving operation of the receivers 141, 142 is stopped, and when the transmitters 134, 135 While the transmission operation is kept stopped, the reception operation of the receivers 141, 142 is allowed. In addition, when the output terminals of the transmitters 134 and 135 and the input terminals of the receivers 141, 142 are kept in a high impedance state by the transmission/reception control signal TD, their transmission operation and reception operation are stopped.

The receiver 141 receives a clock signal CK _d fed through the transmission line 30 and feeds the received signal to a PLL circuit 143 . Furthermore, the receiver 142 receives a transmission signal DR fed through the transmission line 30 and feeds the received signal to a decoder 144 .

The PLL circuit 143 outputs a reference signal CK _dm synchronized with the clock signal CK _d fed from the receiver 141 , and feeds the generated signal to the decoder 144 . In addition, the feed clock signal CK _d is output from the transmission/reception unit 13 .

The decoder 144 performs a decoding process on the transmission signal DR received by the receiver 142 . In the decoding process, the transmission signal DR affected by the equalization of the DC level and the minimization of the number of inversions of the logic level is restored to an original signal. The multiplexed signal DM _d obtained by the decoding process is fed to a demultiplexer 145 . Furthermore, said decoder 144 generates an enable signal EN _d which allows a distinction between active display periods and blanking periods of said multiplexed signal DM _d and is fed to said demultiplexing signal DM d device 145, and output from the transmission/reception unit 13. Incidentally, the decoding process of the transmission signal DR and the generation of the enable signal EN _d in the decoder 144 are performed at a certain timing based on the reference signal CK _dm fed from the PLL circuit 143 .

Based on the enable signal EN _d , the demultiplexer 145 demultiplexes the multiplexed signal DM _d into a signal during an active display period and a signal during a blanking period, and outputs the Decomposed signal. Here, the signal during the effective display period is output as a serial image signal DG _d , and if the serial image signal DG _d is a blue serial image signal DG _dB , the signal during the blanking period is output as Output as synchronous signal SY _d . In this way, the transmission/reception unit 13 can bidirectionally transmit the serial image signal DG and the clock signal CK through the transmission line 30 .

The serial image signal DG _d , synchronization signal SY _d and clock signal CK _d output from the transmission/reception unit 13 are fed to an image reception processing unit 15 as shown in FIG. 1 . The image reception processing unit 15 performs image display and the like of its contents based on the fed serial image signal _DGd of the three primary colors, the clock signal _CKd , the synchronization signal _SYd, and the like.

The control unit 19 communicates with the control unit 29 of the signal transmission device 20 through the low-speed serial bus 310 of the transmission line 30, so as to determine the type of the signal transmission device 20, and generate an image based on the determined result Control signal TG _a . The image control signal TG _a is fed to the image transmission processing unit 11, whereby the number of colors and the resolution of a digital serial image signal DG generated by the image transmission processing unit 11 are adjusted to suit the Signal transmission device 20. Furthermore, the control unit 19 generates operation control signals TM _a and TM _d in order to control the operations of the multiplexer 131 and the demultiplexer 145 , respectively. Also, it generates the transmission/reception control signal TD, feeds the generated signal to the transmission/reception unit 13, so as to set the signal transmission direction of the high-speed serial buses 301-307.

The signal transmission device 20 connected to the signal transmission device 10 through the transmission line 30 includes a transmission/reception unit 23 similar in structure to the transmission/reception unit 13, and the signal transmission device 20 passes through the transmission/reception unit 23 is connected with the transmission line 30.

A serial image signal DG _b , synchronization signal SY _b , etc. of the three primary colors output from the decoder of the transmission/reception unit 23, and a clock signal CK _b output from the PLL circuit thereof, are fed to a Image receiving processing unit 25 . This image reception processing unit 25 is similar to the image reception processing unit 15, and performs image display and the like of its contents.

And, similar to the image transmission processing unit 11, an image transmission processing unit 27 generates a serial image signal DG _c of the three primary colors, a synchronization signal SY _c and an enabling signal EN _c , and feeds the generated signal to to the decoder of the transmission/reception unit 23 in order to generate a transmission signal. In addition, the image transmission processing unit 27 generates a clock signal CK _c , and then feeds the generated signal to the PLL circuit of the transmission/reception unit 23, so that the transmission signal and the clock signal CK _c are transmitted through the transmission line 30 to the signal transmission device 10.

In this way, when the signal transmission devices 10 and 20 are configured as if the signal transmission direction of the TMDS link is bidirectional, the signal transmission devices 10 and 20 are connected to each other, and the control unit 19 of the signal transmission device 10 and the signal transmission Communication between the control unit 29 of the device 20 is enabled via said low-speed serial bus 310 with plug-and-play functionality. The type, model, etc. of the corresponding signal transmission equipment are determined due to communication, and the resolution and the number of colors of the serial image signal DG generated by the image transmission processing unit 11 or 27 are adjusted so as to be compatible with the corresponding Compatible with signal transmission equipment. In addition, a clock signal CK, a synchronization signal SY, etc. corresponding to the serial image signal DG are also generated.

Here, both the transmission/reception unit 13 of the signal transmission device 10 and the transmission/reception unit 23 of the signal transmission device 20 can realize bidirectional communication through the high-speed serial buses 301-307 described above. Therefore, when the signal transmission direction of each high-speed serial bus is controlled by the transmission/reception control signal TD from the control unit 19 or 29, the image signal of the content can be fed from the signal transmission device 10 to all The signal transmission device 20, at the same time, the image signal of the content can be fed from the signal transmission device 20 to the signal transmission device 10. Therefore, the transmission line 30 can be used to connect a device, and this device can not only realize one-way communication with the well-known interface of DVI standard between a computer device and a monitor device, but also the input and output of image signals Like a video record/playback device.

The transmission of image signals has been described above. In this regard, when the high-speed serial buses 301-306 are used to transmit data of six channels as in the TMDS link, an image signal can Can be transmitted, provided that the image signal to be transmitted has a small data volume.

Figure 3 shows the bandwidth of the TMDS link in the upper part.

The axis of abscissa represents the pixel bandwidth of 0-300 (Mpic/sec), and each file is 50 (Mpic/sec), while the axis of ordinate represents the single-channel bandwidth of 0-2 (Gbs), and each file is 0.5 ( Gbs).

In addition, corresponding to the bandwidth diagram of FIG. 3 , the lower part of FIG. 3 shows the situations of SXGA (1280*1024) and UXGA (1600*1200) pixels on the horizontal axis. Also, vertical frequency and blanking period in the case of displaying pixels on an LCD device and a CRT display device are shown on the vertical axis.

Let us assume a concrete example that the data volume of the image signal to be transmitted is not more than about 165 (Mpic/sec). Assume that there is an image display with a size of SXGA (1280 pixels*1024 pixels) and a vertical frequency of 85 (Hz) and GTF blanking, or assume that there is an image display with a size of UXGA (1600 pixels*1200 pixels) and a vertical The image display under the condition of the frequency of 60 (Hz) and GTF blanking, the image signal can be transmitted by a high-speed serial bus of one link (three channels). However, it is assumed that there is an image display having a size of UXGA (1600 pixels*1200 pixels) and under the condition of a vertical frequency of 75 (Hz) and GTF blanking or under the condition of a vertical frequency of 85 (Hz) and GTF blanking , then use a high-speed serial bus with two links (six channels), as shown on the right side of Figure 3, where the dotted line corresponds to 165 (Mpic/sec).

As described above, when the image signal is transmitted using the three-channel high-speed serial bus, a signal other than the image signal, such as an audio signal, can also be easily transmitted using the remaining high-speed serial bus that is not used to transmit the image signal. Transport well.

FIG. 4 shows a third embodiment of the present invention in which an image signal and an audio signal are fed from a signal transmission device 35 to a signal transmission device 40 . Incidentally, in FIG. 4 , the same reference numerals denote corresponding parts to those shown in FIG. 1 . In addition, blocks with like numbers perform similar functions to those shown in FIG. 1 .

The signal transmission device 35 includes an image transmission processing unit 11 and an audio transmission processing unit 31 capable of generating audio signals. The image transmission processing unit 11 generates a serial image signal DG _a , a synchronization signal SY _a and an enable signal EN _a , and feeds the generated signals to a processing/receiving unit 13 . On the other hand, based on a sound output control signal TA _a fed from a control unit 39 to be described below, the sound transmission processing unit 31 generates the sound signal DA _a , which will generate the sound signal DA _a at predetermined output to the processing/receiving unit 13 within the time limit. Incidentally, the sound signal _{DA a} generated by the sound transmission processing unit 31 is based on a clock signal _{CK a} fed from the image transmission processing unit 11 to the sound transmission processing unit 31, and It is realized at a certain timing so as to be synchronized with the serial image signal DG _a .

Adapted to the signal transmission device 40, based on its communication with the control unit 49 of the signal transmission device 40, the control unit 39 controls the image signal transmitted from the signal transmission device 35 to the signal transmission device 40 Make adjustments. And, the control unit 39 feeds a transmission/reception control signal TD to the transmission/reception unit 13, thus, four high-speed serial buses for transmitting data and one high-speed serial bus for transmitting a clock The signal transmission direction is set as the direction from the signal transmission device 35 to the signal transmission device 40 .

As mentioned above, the transmission/reception unit 13 transmits the serial image signal DG _a of the three primary colors through three of the four data transmission high-speed serial buses, and the signal transmission direction of the four data transmission high-speed serial buses has been determined. It is set in the direction from the signal transmission device 35 to the signal transmission device 40 . Furthermore, the unit 13 generates a serial transmission signal of a voice by performing decoding processing on the voice signal DA _a , and transmits the serial transmission signal through one of the four data transmission high-speed serial buses. .

The signal transmission device 40 includes a transmission/reception unit 23 similar in structure to the transmission/reception unit 13 , and is connected to the transmission line 30 through the transmission/reception unit 23 .

The serial image signal DG _b output from the decoder of the transmission/reception unit 23, the synchronization signal SY _b , etc., and a clock signal CK _b output from the PLL circuit of the transmission/reception unit 23 are fed to An image receiving processing unit 25, the image of whose content is displayed. Incidentally, the clock signal CK _b is also fed to a sound reception processing unit 46 .

An audio signal DA _b output from the decoder of the transmission/reception unit 23 is fed to the audio reception processing unit 46 . The sound receiving processing unit 46 generates an analog sound signal according to the fed sound signal DA _b and the clock signal CK _b , and provides a sound output based on the analog sound signal.

In this way, the serial signal can be transmitted through three data transmission high-speed serial buses, and at the same time, the sound signal uses the idle data transmission high-speed serial bus that is not used to transmit any serial image signals. The bus is transmitted. In this way, the transmission line 30 can be fully utilized.

Alternatively, as described above, since a blanking period is reserved in a standard such as GTF specified by VESA, the sound signal may also be transmitted using a blanking period.

FIG. 5 is a fourth embodiment of the present invention, the structure of which shows the situation in which an audio signal is fed from a signal transmission device 50 to a signal transmission device 60 during the blanking period. Incidentally, the same reference numerals denote parts corresponding to those in FIGS. 1 and 4 . In addition, blocks with the same numerals perform corresponding functions as those shown in FIGS. 1 and 4 .

The signal transmission device 50 includes an image transmission processing unit 11 and a sound transmission processing unit 31 . The image transmission processing unit 11 generates a serial image signal DG _a , a synchronization signal SY _a , an enable signal EN _a and a clock signal CK _a , and feeds the generated signals to a transmission/reception unit 13 . The clock signal CK _a and the enable signal EN _a are also fed to the sound transmission processing unit 31 . The sound transmission processing unit 31 generates a _sound signal DA _a at a certain timing based on the clock signal CK _a , and feeds the generated sound signal DA _a to the transmission/ Receiving unit 13.

Here, a high-speed serial bus for transmitting a blue serial image signal DG _aB also transmits the synchronization signal SY _a during the blanking period. Thus, the sound signal DA _a is fed to the multiplexer 131 of the transmission/reception unit 13, and the transmission/reception unit 13 is fed to a red serial image signal DG _aR or a green serial Image signal DG _aG .

Based on the enable signal EN _a , the multiplexer 131 selects the serial image signal DG _aR or DG _aG and the audio signal DA _a to generate a multiplexed signal DM _a , which is effectively displayed During the interval, the multiplexed signal DM _a is composed of the serial image signal DG _aR or DG _aG , while during the blanking interval it is composed of the audio signal DA _a , as shown in FIG. 6 . The multiplex signal DM a composed of the serial image signal DG _aR or DG _aG and the sound signal _{DA a is} encoded and transmitted as a serial transmission signal DT.

The signal transmission device 60 includes a transmission/reception unit 23 similar in structure to the transmission/reception unit 13 . In the transmission/reception unit 23, a multiplexed signal DM _b output from its decoder is fed to its demultiplexer, thereby decomposing and outputting a serial image signal DG _bR or DG _b-G and An audio signal DA _b . The serial image signal DG _b , synchronization signal SY _b , etc. output from the transmission/reception unit 23 are fed to an image reception processing unit 25 capable of presenting images of contents. Furthermore, the audio signal _DAb output from the transmission/reception unit 23 is fed to an audio reception processing unit 66, which provides an audio output.

When the sound signal DA _a is thus transmitted using the blanking period, not only the serial image signal DG _a but also the sound signal DA _a can be transmitted using three high-speed serial buses for data transmission.

At the same time, as mentioned above, two signal transmission devices are connected through the transmission line 30, and the communication between the signal transmission devices is established. However, since the transmission line 30 can transmit signals bidirectionally, although it is a high-speed serial bus different from the interface of the DVI standard, a network can be established by connecting a plurality of signal transmission devices through such a transmission line 30 .

Fig. 7 is the fifth embodiment of the present invention, shows the situation that forms a network by connecting a set-top box 70, a monitor device 80, a signal record/playback device 90 and a computer device 100, just as a network comprising multiple Network structure of signal transmission equipment. For network connection purposes, each device has two connectors to be able to connect two transmission lines 30 .

A connector of the monitor device 80 is connected to a connector of the set top box 70 through the transmission line _30-1 . In addition, one connector of the signal recording/playback device 90 is connected to the other connector of the monitor device 80 through a transmission line _30-2 . Also, one connector of the computer device 100 is connected to the other connector of the signal recording/playback device 90 through a transmission line _30-3 . In this way, these devices form a daisy chain connection through the transmission line 30, thereby establishing a network.

In the case of having such a network structure, based on the three-primary-color serial image signal of the baseband output from the set-top box 70, the image of the content can be displayed on the screen of the monitor device 80, while at the same time, the baseband A serial image signal can be fed to the signal recording/playback device 90 to record an image of the content on a recording medium. Also, the image of the content can be easily processed by the computer device 100 in such a manner that a serial image signal having three primary colors of the baseband is fed from the signal recording/playback device 90 to the computer device 100 . Since the transmission line 30 can be bidirectionally transmitted, by feeding the baseband serial image signal from the computer device 100 to the signal recording/playback device 90, a computer image can be recorded on the recording medium, or, through the signal The record/playback device 90 feeds them to the monitor device 80 to be displayed.

Furthermore, assuming that a signal is transmitted between a pair of devices through a high-speed serial bus in accordance with communication between the control units of the respective devices, or that the high-speed serial bus connected to another device is electrically disconnected, The pair of devices can then be operated in a point-to-point connection regardless of the way the network is connected.

Such as, the set-top box 70 has received the image signal whose content is copyrighted, the control unit of the set-top box 70 communicates with the control unit of the monitor device 80 to determine that the equipment connected to the set-top box 70 does not have the ability to record the image signal. function, and then, the image signal is transmitted to the monitor device 80 through the high-speed serial bus. In addition, when the control unit of the monitor device 80 communicates with the control unit of the signal recording/playback device 90 connected to the monitor device 80, it can be determined that the device connected to the monitor device 80 has a function of recording image signals, Then, the high-speed serial bus is electrically disconnected, that is, a transmitter and a receiver connected to the transmission line _30-2 start to be in a high-impedance state. At this time, the image signal whose content is copyrighted is not transmitted to the signal recording/playback device 90, and the network can be operated between the set-top box 70 and the monitor device 80 like a point-to-point connection.

Next, a sixth embodiment of the present invention will be described.

To allow network connections, each device has two connectors. Therefore, as shown in FIG. 8, when devices each having two connectors are connected in a point-to-point manner, two transmission lines can also be connected with such connectors. At this time, the serial image signal can be transmitted through these two transmission lines, so even when the data amount of the image to be displayed on the monitor device is large, as in an air traffic control system or the like, they can be Can be transmitted using baseband.

Incidentally, although image signals and sound signals can be transmitted as described above, signals that can be transmitted are not limited to image and sound signals, and various data signals can also be transmitted well. In addition, high-speed serial buses are not limited to such a structure that the signal transmission direction of the TMDS link is changed to bidirectional transmission, but they may of course have such a structure that, for example, transmission lines of the LVDS (Low Voltage Differential Signaling) standard Made to be bidirectional.

According to the present invention, in the case of transmitting signals through a transmission line consisting of a plurality of high-speed serial buses and a low-speed serial bus whose transmission speed is lower than that of the high-speed serial bus, signal transmission through a plurality of high-speed serial buses Operations are controlled based on the results of communications through the low-speed serial bus. Therefore, wideband digital signals can be bidirectionally transmitted at high speed.

In addition, signal transmission directions of the plurality of high-speed serial buses may be independently set based on communication results through the low-speed serial buses. Thus, for example, when an image signal is transmitted, an audio signal or the like can also be transmitted via the free high-speed serial bus. Moreover, various signals can be transmitted in a time-division manner through the high-speed serial bus. Therefore, even if the high-speed serial bus is not idle, a sound signal or the like can be transmitted using the blanking period of the image signal, and efficient signal transmission can be realized.

Also, when each signal transmission device is allowed to transmit signals through a plurality of transmission lines, network connection becomes possible. Also, when signal transmission devices are connected in a point-to-point manner instead of a network connection, they can still transmit signals at high speed using multiple transmission lines.

Further, in the case where the opposing signal transmission device has a signal recording function, and in the case where the content to be transmitted has been copyright protected and copy prohibited, transmission via the high-speed serial bus is prohibited. Thus, copyrights are protected and even network connections can be operated in a manner similar to point-to-point connections.

Claims (14)

1. A kind of signal transmission equipment, transmits signal by a transmission line, and this transmission line is made up of a plurality of serial buses with the first transmission speed and a serial bus with the second transmission speed; Described signal transmission equipment comprises: a first communication means for transmitting at least one signal through said plurality of serial buses having a first transmission speed; and second communication means for transmitting a signal via said one serial bus having a second transmission speed; the second communication device controls a signal transmission operation of the first communication device based on a result of communication through the serial bus having the second transmission speed; and Signal transmission directions of the plurality of serial buses having the first transmission speed may be independently set by the first communication means based on a communication result of the second communication means. 2. The signal transmission device according to claim 1, wherein said first communication means transmits signals independently according to the kind of signals to be transmitted using said plurality of serial buses having said first transmission speed . 3. The signal transmission apparatus according to claim 2, wherein said first communication means transmits an image signal and an image signal different from the image signal through different buses having said first transmission speed of said serial bus. signal of. 4. The signal transmission apparatus according to claim 1, wherein said first communication means transmits various signals in a time-division manner using said serial bus having said first transmission speed. 5. The signal transmission apparatus according to claim 4, wherein said first communication means transmits an image signal through said serial bus having said first transmission speed, also using a blanking period of the image signal to transmit an audio signal. 6. The signal transmission device according to claim 1, wherein a plurality of said first communication means and said second communication means are provided, and a signal is transmitted through a plurality of such transmission lines. 7. The signal transmission device according to claim 1, wherein, based on the communication result, said second communication means determines that a relative signal transmission device has a signal recording function, and when a content to be transmitted is copyrighted and prohibited When copying, it prohibits the communication operation of said first communication means. 8. A signal transmission method, comprising the steps of: Prepare at least two signal transmission devices, each device includes a first communication device for transmitting at least one signal through a plurality of serial buses with a first transmission speed, and a first communication device for transmitting at least one signal through a serial bus with a second transmission speed. A second communication device for transmitting a signal through the row bus; The signal transmission devices are respectively arranged at opposite ends of a transmission line, and the transmission line is composed of a plurality of serial buses with the first transmission speed and a serial bus with the second transmission speed; controlling a signal transmission operation through the serial bus having the first transmission speed based on a result of communication through the serial bus having the second transmission speed; and The signal transmission direction in the signal transmission operation is through the plurality of serial buses having the first transmission speed, and is determined based on a communication result through the serial bus having the second transmission speed The respective serial buses having the first transmission speed are independently set. 9. The signal transmission method according to claim 8, wherein the plurality of serial buses having the first transmission speed are independently used according to the kind of signal to be transmitted. 10. The signal transmission method according to claim 9, wherein an image signal and a signal other than the image signal are transmitted through the plurality of serial buses having the first transmission speed. 11. The signal transmission method according to claim 8, wherein a plurality of signals are transmitted in a time-division manner using the plurality of serial buses having the first transmission speed. 12. The signal transmission method according to claim 11, wherein the image signal is transmitted through the plurality of serial buses having the first transmission speed, and the sound signal is transmitted by using blanking of the image signal transmitted during the period. 13. The signal transmission method according to claim 8, wherein each signal transmission device has a plurality of said first communication means and said second communication means, and signals are transmitted through a plurality of said transmission lines . 14. The signal transmission method according to claim 8, wherein the signal to be transmitted through the serial bus with the first transmission speed is a signal whose content has been copyrighted, and in this case , when the opposing signal transmission device has a signal recording function, signal transmission of the content is prohibited based on a result of communication through said serial bus having said second transmission speed.

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